Telephone-exchange system.



M. L. JOHNSON.

TELEPHONE EXCHANGE SYSTEM.

APPLiCATION FILED JULY l5. 19|2. Lm Patented Ju1y13 1915.

4 SHEETS-SHEET I.

N O .S N w JM L N O T m 2 M wA ATTORNEY M. L. JOHNSON. TELEPHONE EXCHANGE SYSTEM.

APPLICATION FILED JULY I5, I9I2. 1,146,74. Patented July 13, 1915l 4 SHEETS-SHEET 2.

'ii/IG WITNESSES M. L. JOHNSON. TELEPHONE EXCHANGE SYSTEM.

APPLICATION FILED JULY I5. 1912.'

Patented Ju1yl3, 191".

LHJMQ 4 SHEETS-SHEET 3.

XNVENTOR WITNESSES NI. L. JOHNSON.

TELEPHONE 'EXCHANGE SYSTEM.

4 SHEETS-SHEET 4.

N .w MW. N N R H To. Tw T R. A mL Nm/W WT m9, .O M

- WITNESSES montrent I.. JOHNSON,

OF CI-IICAGO, ILLINOIS, ASSIGNOR, BY MESNE ASSIGNMENTS, TO

K'Bl-.QOOK COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

TEIEPHONE-EXCHANGE SYSTEM.

maceta.

Specification of Letters Patent. v Patented July 13, 1915 Application led l'uly 15, 1912. Serial No. 709,430.

extending calling lines into connections with operator selected link connectors and the extension of the link connectors into connection with additional link connectors further taking part in establishing connection between calling and called lines.

In practising my invention a receiving operator operates a link selector switch to bring the iirst link connector into connection with the switch of such selector andl thereafter operates the electro-magnetic mechanism of a second switch to connect the first link connector with the second link connector.

In' one Vembodiment of the invention, to

which embodiment the invention is not to' be limited, the second switchis individual to the second link connector and the second link connector is individual to the switch of an ordinary connector switch such as is employed in automatic telephone practice whereby the final step in the operation oi connecting calling and called lines may also be eiiected by the operator who has thusy extended a calling line.

The system described is one which may include nine hundred lines. If the system has more lines there would be additional link connectors and additional' operator c'ontrolled selector switches for including them in the telephone circuit to be established.

I will explain my invention more fully by reference to the accompanying showing the preferred embodiment thereoi and in which Figure l is a view generally outlining the equipment whichI employ and Figs. 2,

3 and 4, taken collectivelynnd in numerical order, represent the system 1n more of its link select or 5. drawingsswitches 5,.there being two switches details7 the equipment illustrated being.

adapted to a-nine hundred linel system 1n which an operator receiving a call may establish the entire connection between calling and called subscribers, though the invention is not to be limited to the number of lines employed nor to the establishment ofthe final connection by .the operator between the called line and the final link connector selected by the receiving operator and brought into connection with a calling line.

Referring first particularly to Fig. 1, I have there shown (in the case of a nine hundred line system) al subscribers station 11]. in the first group of one hundred lines and another lsubscribers station 201 in the second group of one hundred lines, the lines being divided into ninegroups oit' one hundred lilies, each, the irst line in the first group being'numbered 100. 1

When a calling subscriber (say at station 111) initiates a call the telephone equipment 1 at some idle operators position is selected by an operator selector switch'Q which is set into operation bythe equipment of a calling line and which is arrested when waiting contacts` peculiar to an'idle operator are encountered by the traveling wipers of the idle operator selector switch. Each operator selector` switch 2 includes equipment, generally illustrated in Fig. 1, but more fully illustrated inthe remaining figures, by which the switching apparatus 3 belonging to the selected idle operator is extended into connection withan` operator controlled link connector switch 4. The wipers of the selector switches 4 are shown as being individual to the subscribers lines,

though the invention is not to be thus restricted. Each selectorswitch 4, in the sys- .tem described,v may be provided with nine vsets ot waiting contacts, one contact ot each such set being illust-ratedin Fig. l. Each suchset of contacts is multiply-related with and is individual to two sets, and only two sets, of waitingcontacts each in a second Each `first link selector switch 4 thus is vrelated tol certa-in waiting contacts of eighteen .second li-nk selector 5 for each set' of contacts belonging to each switch 4, these two switches 5 being, as a pair, related (by means ot' its one hundred sets of waiting contacts) with one hundred ico eration' of the rst of the two switches 5 that CIR the switches 5 lof one'hundred lines in which the desired switches 4, each set of waiting contacts of each switch 5 being individual to one switch 4.

In the system assumed there are one hundred sixty-two switches 5 for the ninehundred lines and as each switch 5 is individual to a connector switch 6 there are one hundred sixty two such connector switches, each accessible to each of the lines of the group of one hundred to which such selector switches are apportioned. As illustrated, each pair of switches 5 is accessible only to the lines of the associate group of one hundred lines that has the switches 4, while the pair of associated connector switches 6 is also limited to such association with calling lines in the group of one hundred lines to which the switches 5 and 6 are apportioned, though the invention is obviously not to be restricted to such an embodiment. The set of wipers of each selec- 'tor switch 5 is individual to a set of wipers of the associate connector switch 6 which may be of the usual type employed in automatic telephone exchange practice when the operator is to complete` the entire connection. lVhile the waiting contacts of each pair of switches 5 are individual to a group of one hundred lilies each group of one hundred lines has apportioned thereto the wipers of nine pairs of switches 5 and their waiting contacts, each pair of such wipers being individual to a group of one hundred lines. In this way any of the nine hundred lines, when a calling line, may have access to some switch 5 whose wipers are individual to the group of one hundred lines that includes the line desired by the calling line. British Patent 1298 of 1910 may be referred to as illustrating thc general operation of connector switches such as are indicated at 6. Van Devcnters Telephonology, page 580, illustrates the mechanism whichv may be employed in the connector switches and some of this mechanism is employed in the construction of switches 4 and 5.

lf' the desired line is in the first group of one hundred the operator steps the wipers of switch 4 which she employs into engagement with the first set of waiting contacts. lf the desired line is in the second group of one hundred these wipers are brought into connection with the second set of waiting contacts, and so on, there being, as is now understood, nine sets ot these waiting contacts for each switch 4, each set of contacts'being peculiar to link connectors 7 that in tfurn are each individual to -a pair of switches 5. The operator having arbitrarily stepped the wipers of the first link selector 4 into connection with a link 7 pertaining to and 6 belonging to the group line is included, automatically effects the opW is in order (one switch 5 being operated before the otherswitch 5 can be operated if both switches 5 are idle at the time of the employment oi one of' them), 'or the remaining of these two switches if one of them is busy, whereby the arbitrarily selected link 7 is automatically connected with the switch 5 and is thereby automatically extended into connection with connector switch G associated therewith that is to be employed in further extending or finally completing the connection. After a switch 5, say the upper switch in F l, has been thus automatically brought into connection with the operator selected link 7, the contacts of the remaining switch 5 in multiple with the contacts of the first switch 5 that establish the connection between the connector switch 6 and 'the employed link 7 is made busy so that the second switch, when set into operation to entend another calling line in the. same group with line lll, will not stop upon such con tacts thus made busy but will pass on into engagement with the contacts of the newly operated selected link 7, an additional line 112 being illustrated with a first link selector switch 4 in association with the two second link selector switches 5 belonging to the switches 4 of the first group of one hundred lines, Thus the lines of a group are adapted to have access to the first switch 5 in order, if both of Vthese switches are idle and is adapted to have access to the idle one of these two switches 5 if the other -is busy, it

`being estimated that eighteen switches 5 in the nine hundred line system illustrated will be sufficient for each group of one hundred such lines, each of the nine sets of waiting contacts of the first link selectors 4 belonging to the first group of one hundred lines having the waiting contacts of two switches 5 individual thereto as has been described, the first waiting contacts of one switch 4 being connected with the first waiting contacts of two switches 5 belonging to the group of first one hundred lines, the first contacts of the next switch 4 of the same group being connected with the next contacts of these two switches 5, the first contacts of the third lswitch 4 (not shown) of the same group beiirig connected with the next contacts of those twn switches 5, and so on, there thus being one hundred sets ot waiting contacts for each switch 5 where each line has :lflfirst' link selector 4 individual thereto.

The second contacts of each switch 4 in ay group are similarly related to the pair of second link selectors 5 pertaining to the second group of ,ene hundred lines, the third contacts of each switch 4 in a group are similarly related to the pair of second link selectors 5lfpeitaining to the third group ol one hundred lines, and so on, the final contacts of the'rswitches 4,l as the invention is illustrated, being similarly associated with i tion with station 112, the operator will ma'J nipulate the device 3 to bring the wipers of the first link selector 4 ot the calling line into connection with the first set of waiting contacts pertaining to the single link selector 7 individual to the employed selector 4 and having waiting contacts in the switches 5 that pertain to the first group of one hundred lines. The selected one of the two switches 5 vis set into operation to cause its wipers to stop upon the waiting contacts pertaining to the operator selected -link 7 thereby to associate the link connectors 6 individual to the employed switch 5 with the employed link 7 The connector switch'6 shown being of the type employed in automatic practice, the operator manipulates the same device 3 and causes the wipers of the connector' switch 6 to be stepped -up to the level of that bank of waiting contacts corresponding to the tens in which waiting contacts of the desired line are included whereafterthe same device 3 serves to step the wipers of the employed connector switch 6 around until these wipers encounter the waiting contacts of the desired line, the usual busy test being conveyed if the desired line is busy and the usual signaling circuit being established if the desired line is free. As the invention is practised, two of the wipers of the employed link selector switch 4 are connected with a calling line and thus constitute calling line extensions and in a measure may be said to constitute links in the connection between calling and called lines. I have shown no selector switches for bringing these wipers into 'connection with calling lines and have therefore called the switches 4 the iirst` link connector switches but I do not intend thereby to limit myself to the non-employment of preceding selectorv switches, switches 4 are shown as being `electro-magnetically operated, I do not wish to .be limited to this feature for enabling the operator 'arbitrarily to select link connectors 7.

term the switches 4 the first link selector switches as they are here shown as being the first to be operated and-which` the operator employs in arbitrarily appropriating link connectors 7. I term` the switches 5 second. link selector switches as they are the second switches to operate automatically to become connected with operator appropriated links 7.

The invention will now be further eX-. plained in connection with Figs. 2,13 and 4 in which I' have illustrated the equipment associated with two lines (111 and 112) in the same group of one hundred lines. Each telephone station illustrated includes a telephone switch hook 8 having a normal contact serving, when the telephone receiver 9 Ais upon thel switch hook, to establish a bridge connection between the line sides that includes a signal bell 1 0 and condenser 11. The switch hook has an alternate contact serving when the telephone receiver is removed therefromwto complete a metallic bridge connection between the, line sides that includesthe telephone receiver 9 and the telephone transmitter 12. Each line terminates at the exchange in the armature switches of a cut oli relay 13 whose normal contacts are connected with the intermediate armature switches of a switching relay 14,

the normal contents of these latter armature switches being connected with'the upper and lower windings of a line relay 15, the lower winding being directly grounded while the upper winding 'is grounded through the common battery 16. The line relay 15 is thus included in a closed circuitwhenv the telephone receiver at a calling station is re- Inovedfrom its vswitch hook.

When the relay 15 is energized a circuit is established which may be traced from its upper grol'mded armature switch, the alternate contact of such armature switch, the sluggishly'operating interrupter relay 17, the rotarv magnet 18, the side switch wiper 19 in its first position, to the grounded common battery 16. The rotary magnet 18 now sets the wipers 20, 21, 22, 23, 24 and '25 into step by step movement until the wiper 22 encounters an ungrounded waiting contact whereupon all of these wipers are stopped, since thecircuit for the private magnet 26 (which circuit `was established uponv the initial operation of the rotarv magnet 18) is opened at the` wiper 22, said private magnet then causing the side switch wipers 19 and 27 tostep to their second positions. then the side switch wiper 19 steps into its second position circuit for the rotary magnet 18 is opened. lVhen the side switch wiper 27 is stepped into its second position the associate wiper 22 is' being multiply related with similar contacts of, other switches. rlhe operators telephone 1 has telephone conductors provided with multiply related contacts provided for the wipers 20 in the different operator selector switches and multiply related contacts provided itor the wipers 2l in the different operator selector switches, whereby the wipers 20 and 21 `that are brought to rest connect some operators telephone set 1 with the calling line. The calling subscriber tells the operator the number of the desired line and the operator" thereafter manipulates a suitable circuit interrupter device, simply shown as a key 3, for interrupting the circuit of the line relay 28, the `circuit for this relay having been previously established dueto a circuit from the grounded battery 16, the side switch wiper 19 in its second position, the relay 29, the lowermost armature switch of relay 15, to ground, the upper armature switch of the now energized relay 29 establishing a circuitwhich may be traced from the upper grounded winding of relay- 28, the upper armature switch ot' relay 30 and its normal contact, the upper armature s\vitch-of.relay 29 and its then engaged contact, the wiperl 23 and its engaged contact the circuit interrupting device 3, the wiper 24 and its` then engaged contact, the intermediate armature of relay 29. the intermediate armature switch of relay 30, the lower coil of relay 28, to the grounded battery 16. The relay 28 is, by means of the device 3, operator controlled and whenever the -device 3 is actuated the circuit for therelay`28 is broken whereupon the lower armatureot the relay 28 engages its normal Contact to establish a circuit from this lower armature, which is grounded, the normal contact of such armature, the armature switch ot sluggishly operating relay 31 (whose circuit was previously established when the relay 28 was energized. as will be apparent) the alternate Contact of this latter armature switch, the sluggishly operating relay 32, the rotary magnet 33, the common battery 16, to ground. The rotary magnet33 is thus operated as often as the operator desires to cau-se the arbitrarv movement of the wipers 34, 35, 36 and 37 into connection with the llink connector (indicated at 7 in Fig. l) which the operator has appropriated for use and which link connector is of such relationship as to enable it to he employed for uniting the desired line with the calling line. The waiting contacts engaged by the wipers 34, 36 and 37 are vprovided with conductors 71. 72. 7, 74 extend therefrom to equipment that pertains to the link selector switches 5, conductors 71, 72, and 74 extending, directly to waiting contacts provided for the wipers 38, 39 and 40, while the conductor 73 extends to electro-magnets 41 whose armature that switches are grounded upon the associate waiting contacts'of wipers 42 of the diierent switches 5.

When the wiper 36 engages a conductor 7 3 pertaining to the link connector arbitrarily selected by the operator, a circuit is established which is traced from the grounded upper armature switch of relay 28 and its then engaged Contact, the upper armature switch of relay 32 and its then engaged contact (this armature switch being free of its Contact during the time that the wipers 34 to 37 are being stepped around owing tothe sluggishness of the relay 32) the wiper 36, the selected conductor 73, the relay 41, the grounded battery 16, to ground. The armature switch of relay 41 then engages its alternate contact and establishes a circuit armature switch of relay 41, its alternate contact, the upper armature switch of relay 43 and its normal contact, the upper intermediatearmature switch of relay 44 and its normal contact,t the winding of sluggishly operating relay 45, the common battery 16, to ground. The intermediate armature switch of relay 45 then establishes a circuit which may be traced from this armature switch which is grounded, the alternate contact of this armature switch, the rotary magnet 46, the sluggishly operating relay 47, the armature of this relay and its contact, the side switch wiper 48, the grounded battery 16, to-ground. The rotary magnet 46 thereupon causes the Wipers38, 39, 40 and 42 to rotate until the wiper-42 engages a contact from which ground has been removed bythe associate magnet 41 in bringing its armature from its normal to its alternate contact. When the wiper 42 thus encounters a contact from which ground is thus removed the circuit for the private magnet 49 (which was initially established upon the first operation of the rotary magnet'46) is opened whereby the side switch wipers 48, 50 and 501 are moved from their first positions to their second positions. llt maybe said that the circuit initially .established for the private magnet 49 by the rotary magnet 46 may be traced from the grounded armature switch of relay 46 and its then engaged contact, the winding of magnet 49, the side switch wiper 48 in its first position, the battery 16, to ground and that the circuit secondarily established tor the private magnet 49 may be traced from the grounded armature switch of the associate relay 41 and. its normal contact, the wiper 42, the lower armature switch of relay 43, the side switch wiper' 50 in its first position, the magnet 49, the side switch wiper 48 in its lirs't position, the battery 16, t'o ground. The wiper 48, inl being moved to its second position, opens circuit for the rotary magnet 46 so that the wipers 38, 39, 40 and which may be traced from the grounded 42 .are arrested. The side switch wiper 48l in its secondposition also closes a circuit for' the relay 44 which may be traced from the wipers 34 and 37, the circuitv for the magnet 30 being traceable from the grounded battery 16, the side switch wiper 521 in its second position, the relay 30, the wiper 35, the conductor 72, the wiper 39, the side switch wiper 501, to the then grounded upper armature s witch of relay v68. The side switch wiper 521 is brought into second position by the private magnet 522 .whose circuit was maintained duringthe impulses, occasioned at 3, by the sluggishly operating relay 32. When the series of impulses A,is ended the magnet 522 is denergized and the side switch wiper 521 is placed in second position. A relay 53 is in metallic bridge ofthe conductors extending to the wipers 51 and 52 and circuit therefor is'completed by way of the key 3 at theselected operators position. The operator by means of the key 3, may interrupt the circuit .of the relay 53 and cause the operation of the connector switch in a manner well known, it being sufficient, to enable those skilled in the art to understand the illustration, to name the parts of the connector switch dia grammatically illustrat-ed. The connector switch shown 1ncludes a vertical magnet 54, rotary magnet 55, ringing magnet 56, release magnet 57, oiil normal switch 58, ringing generator 59, private relay 60, private control relay 61, side switch wipers 51, 52, 62 and 63, armatures 64, 65 of the ringing relay 56, ringing cutoii relay66, back bridge relay 67, release control relay 68, impulse control relay 69, busy tone device 70, and the wipers 71, 72 and 73, the wipers 71 and 73 being included in the telephone circuit` when established between the calling and called lines.

Then the switching relay 44 of the switch 5 was brought into operation circuit of relay 45 was opened and the ground established at the lowermost armature switch of this relay 45 was removed but is replaced at the upper armature switch of relay 68, relay 45 being suiiiciently sluggish in action to permit ground to be established at the upper armature switch of relay 68 before it 1 is removed at the lower armature switch of relay 45. Thus the relay 44 of switch 5 is maintained energized until there is no metallic bridge between the talking sides of the circuit between calling and called stations so that when the telephone 'receivers at both of these stations are upon their hooks the circuit for the magnet 44 is broken .at the upper armature switch of relay 68,

the circuit of relay 68 being dependent upon the relays 53 and 67 as willbe wellunderstood by those skilled in the art: When the waiting contacts of the desired line have been engaged the operator manipulates herv key 74 to establish a circuit which may be traced from the grounded battery 16, the

contact-s of the key 74, the' wiper" 25, the lowermost armature switch of relay 29, the winding of relay 14, the wiper 35, the conductor 72, the wiper.. 39,'wiper 501 in its second position, to the upper armature switch of relay 68 which is then grounded..

The relay 14 is thereby energized to bring its intermediate armature switches into engagement with their alternate contacts whereby the calling line is brought into direct connection with the employed switch 4 and the operators telephone equipment 1 is cut out of circuit. `The operators telephone set is cut out owing to the deenergization of relay 15 which causes the release magnet 75 to be included in a circuit that includesthe grounded battery 16, the previously establishedo normal contact 76, said magnet 75, the uppermost grounded arfmature switch of relay 15 and its normal contact. All of the Wipers of the operator selector switch 2*-are now restored to normal and the operators telephone outfit is cut out of circuit. When the relay 14 was energized it established a' locking circuit through itself which is traced from the grounded battery 16,-the lowermost armature switch of relay ,14 and its then engaged contact, the winding of relay 14, the wiper 35, the conductor 72,*the wiper 39, the wiper 501 in its second position, the upper armature switch of relay 68 to ground. lVhen therelay 68 is denergized in, the manner which has been described this locking circuit is broken so that the calling line equipment is restored to normall lVhen the relay 68 of the connector switch is denergized (which can only occur when the receivers at the calling and desired stations are upon their switch hooks) the connector switch is restored to normal in a manner well known and the wipers of switches 4 and 5 are restored to normal owing to the denergization of relays 44 and 30. When relay 44 is deenergized the-circuit for the release magnet 43 is closed from the grounded battery 16, the previously closed off normal switchv 77,- the release magnet 43, the lower intermediate armature switch of relay 44, the intermediate armature switch of relay 45, to

.ground.v The magnet '43 thereupon causes` i ates from the station 111.

' switchl of relay cuit is established for release magnetS which may be traced from the grounded battery 16 through the previously closed off normal switch 79, the release magnet 78, the lowermost armature switch of relay 30, the armature switch of relay 31, and its normal contact, the lower armature switch of relay 28 and its normal contact, to ground.

' rlhe release magnet 7S thereupon. restores the side switch wiper 521 and the wipers 34, 35, 36 and 37 to normal, and as circuit for relay 1e is broken 'at the upper armature switch of relay 68 the entire equipment is restored to normal.

l have described a connection which initi- The equipment illustrated in connection with station 112 is similar to that illustrated in connection with station 111 and similar parts are given similar characters ot reference. The two switches 5 the -tirst group of one hundred lines and, if both switches are idle, one of these switches is subject to employment before the pther. 1f one of these switches is busy the other switch is then alone subject to employment by a new calling subscriber in the particular group of one hundred lines. In order that one switch 5 may be employed in advance of another when both switches are idle I make the alternate contacts of the relay 41 of the switches 4 of each group of one hundred lines common to the lead 80 which goes to the. iirst switch 5 and there terminates at the upper armature of release magnet 43. lVhen this armature is inv normal position and when the upper intermediate armature switch of relay 4.4 is in normal position the selector vswitch 5 which has these armatures that are thus connected with alternate contacts oit relays 41 is first subject to operation. When the first switch 5 is employed the upper intermediate armature switch of relay 44 engages its alternate contact whereby circuit is established which may be traced .rom the grounded battery 16, the relay 45 A.of the lower switch 5, the normal contact of the upper intermediate armature switch of relay 44 of. the lower switch 5, and said armature switch, the normal contact of the upper armature switch of relay 43 of the lower switch 5, the upper armature switch of relay 4.5 of the upper switch 5, the alternate contact of the upper intermediate ar .mature switch of relay 4A of the upper switch 5, and thenormal` contact of the u per switch of the relayvv 43 of the upper switch 5, the lead 80, to the attracted grounded armature switch of relay 41 employed by the second seeking line in the group of one hundred.' When any switch 5'is in use it is guarded against further appropriation by the ground established by the armature l1 and the normal contact,

the circuit ou?, relayftl being opened when the illustrated in Fig. 3 pertain tov relay 30 is energized to open the circuit of relay 2S.

Cross reference is made to my co-pending application Serial No. 709,422, iiled July 15, 1912, wherein I have disclosed a telephone exchange system including a plurality of subscribers lines, a plurality of primary intercommunicatiug links between subscribers lilies converging upon a .central point, and normally disconnected from each other, automatically operating connecting means and control devices at the central point for etfecting connections of said links to cach Vother and over said links in opposite directions `from the central point to subscribers lines. Features not herein claimed are claimed in the said copending application.

l/Vhile I have herein shown and particularly described my invention, l do not wish to be limited to the precise details of construction and circuit arrangement illustrated as changes may readily be made without departing from the spirit thereof.

Having thus described my invention, lt claim as new and desire to secure by Letters Patent the following 1. A telephone Xchange system including telephone lines extending from stations to an exchange; link connectors at the exchange for extending calling lines; operator con-v trolled switching apparatus for joining operator controlled link connectors with calling lines; additional link connectors; electro-magnetically operated selector switches for joining the additional link connectors with the aforesaid'link connectors; operator controlled means for setting the selector switches into automatic operation; operator controlled .means for manually governing the extent of automatic operation ofsaid selector switches; and operator controlled electro-magnetically operated connector switches for connecting the selector switches that arc connected with operator appropriated link connectors, with desired lines, A

2. A telephone exchange system including telephone lines extending from stations to an exchange; link connectors at the exchange for extending calling lilies; operator controlled switching apparatus for joining operator selected link connectors with calling lines; additional link connectors; electromagnetically operated selector switches for joining the additional link connectors with the aforesaid link connectors; automatically operating operator controlled means for governing the operation ofr said selector switches and causing them to become automatically connected with the first aforesaid link connectors when they are taken for use; and operator controlled electro-magnetically the selector switches that are connected with 'operator appropriated link connectors,` with desired lines.

i 8. A telephone exchange system including telephone lines extending from stations to an exchange; link connectors at the exchange for extending calling lines; operator controlled switching apparatus for joining operator selected link connectors with calling lines; additional link connectors; electro- 'magnetically operated link selector switches for joining the additional link connectors with the aforesaid link connectors; means governed by said operator controlling switching apparatus and operating over operator operator controlled link connectors with calling lines; additional link connectors; elec.- tro-magnetically operated selector switches for joining the additional link connectors with the aforesaid link connectors; operator controlling means for governing the operation of said selector switches; means for preventing selector switches from remaining in connection with operator appropriated link connectors that are in connection with other selector switches; and operator controlled electro-magnetically operated connector switches for connecting the selector switches that are connected with open.

ator appropriated link connectors, with desired lines.

5. A telephone exchange system including telephone lines extending from stations to an exchange; link connectors at the exchange for :extending calling lines; operator controlled switching apparatus for joining operator selected link connectors with calling lines; additional link connectors; electro-magnetically operated selector switches for joining the additional link connectors with the aforesaid link connectors; automatically operating operator controlled means for governing the operation of said selector switches and causing them to become automatically connected with the first aforesaid link connectors when they are taken for use; means for preventing selector switches from remaining in connection with operator appropriated link connectors that are in connection with other selectory switches; and operator controlled electromagnetically operated connector switches for connecting the selector switches that are con- .governed electro magnetically nected with operator appropriated link connectors, with desired lines.

6. A telephone exchange system including telephone lines extending from stations to an exchange; link connectors at the eX- change for extending calling lines; operator j controlledl switching apparatus for joining operator selected link connectors with calling lines; additional link connectors; electromagnetically operated link selector switchesA for joining the additional link connectors with the aforesaid link connectors; means by said operator controlled switching apparatus and operating over operator selected link connectors forvgoverning the operation of said selector switches to cause them t'o remain in connection with operator selected link connectors; means for preventing selector switches from remaining in connection with operator appropriated `link con'- nectors that are in connection with Iother selector switches; ,and operator controlled operated connector switches for connecting the selector switches that are connected with operator appropriated link connectors, with desired lines.

7; A telephone exchange system including telephone lines extending from stations to an exchange; link connectors 'at the ex-,

change for extending calling lines; operator controlling switching apparatus for joining' operator controlled link connectors with calling lines; additional link connectors electro-magnetically operated selector switches for joining the additional link connectors with the aforesaid link connectors; operator matic operation of said selector switches; operatorsresponsive devices at different operators" positions; and selecting mechanism for selecting operators responsive devices that are free for selection, the link connectors performing their line joining vfunctions independently of said selecting mechanism that selects operators responsive devices.

8. A telephone exchangesystem including telephone lines extending from stations to an exchange; link connectors at the exchange for extending calling lines; operator controlled switching apparatus for joining operator selected link connectors with. calling lines; additional link connectors; electro-magnetically operated .selector switches for joining the additional link 'connectors with the aforesaid link connectors; automatically operating operator Acontrolled means for governing the operation of said selector switches and come automatically connected with the first aforesaid link connectors when they are taken for use; operators responsive devices at different operators positions; and selectcausing them to be-' ioo' vcontrolled means for governing the auto- I ES the link connectors performing their line joining .function independently of said selecting mechanism that selects operators responsive devices. I.

9.' A telephone exchange system including telephone lines extending from stations to an exchange "link connectors at the eX- change for .extending calling lines; operator controlled switching apparatus for joining operator selected link connectors with calling lines; additional link connectors; electro-magnetically operated link selector switches for joining the additional link connectors withthe aforesaid link connectors; means governed 1oy said operator controlled switching apparatus and operating over operator selected link connectors for governing the operationof said selector switches to cause them to remain in connection with operator selected link connectors; operators responsive devices at different operators positi'ons; and selecting mechanism for selecting...hperators responsive devices that are free'` for selection, `the link connectors performing their line'i joining function inde` Vpendently of said selecting mechanism that selects operators responsive devices.

l0. A telephone exchange system including telephone lines extending from stations to an exchange; link connectors at the exchange-for extending calling lines; operator controlled switching apparatus for .joining operateij` ycontrolled link connectors with calling lines additional link connectors electro-magnetically operated selector switches for joining the additional link connectors with theyaforesaid link connectors; operator y controlled means for governing the operation of said selector switches; means for preventing'selector switches from remaining in connection with operator appropriated link connectors that are in connection with other selector switches; operators responsive devices at different operators positions; and selecting mechanism for selecting operators responsive devices that are free for selection, the link connectors performing their line! joining function independently of said selecting mechanism that selects operators responsive devices.

11. A telephone exchange system including telephone lines extending from stations to an exchange; link connectors at the exchange for extending calling lines; operator controlled switching apparatus for joiningl operator selected link connectors with call-- ing lines; additional link connectors; electro-magnetically operatedy selector switches for joining the 'additional link connectors with the aforesaid link connectors; autoy matically operating. operator controlled ,l means for governing the operation of said 'selector ,switches and causing them to -he- `come automatically connected vwith theirst aforesaid linkconnectors when they are 1..

taken for use; means for preventing selector switches from remaining in connection with operator appropriated link connectors that are in connection with other selector switches; operators responsive devices at different operators positions; and selecting mechanism for selecting operators responsive devices that are free for selection, the link connectors performing their line joining function independently of said selecting mechanism that selects operators responsive devices.

l2. A telephone exchange system including telephone lines extending from stations to an exchange; link connectors at the exchange for extending calling lines; operator controlled switching apparatus for joining operator selected link connectors with calling lines; additional link connectors; electro-magnetically operated link selector switches for joining the additionaling over operator selected link connectors for governing the operation of said selector switches to cause them to remain in connection with operator selected link connectors; means for preventing selector switches from remaining in connection with operator appropriated link connectors that are in connection with other selector switches; operators responsive devices at different operators positions; and selecting mechanism for selecting operators responsive devices that are free for selection7 the link connectors performing their line joining function independently of said selecting mechanism that selects operators responsive devices.

13. A telephone exchange system including telephone lines extending from stations to an exchange; link connectors at the exchange for extending calling lines; operator controlled switching apparatus for joining operator controlled link connectors with calling lines; additional link connectors; electro-magnetically operated selector switches for joining the additional link connectors with the aforesaid link connectors;

-operator controlled means for governing the lecting mechanism that selects operators responsive devices.4 n j 14. A telephone exchange system includ,-`

ing telephone lines extending from stations i to' an exchange; link connectors at the exchange for extending calling lines; operator controlled switching apparatus for joining operator selected link connectors with calling lines; additional link connectors; electro-magnetically operated selector switches for joining the additional link connectorswith the aforesaid link connectors; automatically operating operator controlled means for governing the operation of said lselector switches and causing them to hecome automatically connected with the first aforesaid link connectors whenA they are taken for use; operator controlled electroniagnetically operated lconnector switches for connecting the selector switches that are connected with operator appropriated link connect-ors, with desired lines; operators responsive devices at different operators positions; and selecting mechanism for selecting operators responsive devices that are free for selectiomthe link connectors performing their line joining function independently of said selecting-mechanism that selects operatorsA` responsive devices.

l5. A telephone exchange systemvincluding telephonelines extending from stations to an exchange; link connectors at the exchange for extending .calling lines; operator controlled switchingapparatus -for joining operator selected link connectors with calling lines additional linkeonnectors: electro-magnetically operated link selector switches for joining the additional link connectors with the aforesaid link connectors; means governed by said operator controlled switching apparatus, and operating over operator selected link connectors for governing the operation of said i selector switches to cause. them to remain in connection with operator selected link connectors; operator controlled electro-inagnetically operated connector switches for connecting the selector switches that are connected with operator appropriated link connectors. with desired lines; operators responsive devices at different operators positions; and select ing mechanism for selecting operators7 responsive devices that are free for selection, the link connectors performing their line joining function independently7 of said selecting mechanism that selects operators responsive devices.

lo. A telephone exchange system including telephone lines ext-ending from stations to an exchange; link connectors at the exchange for extending calling lines; operator controlled switching apparatus for joining operator controlled link connectors Awith calling lines; additional link connectors; electro magnetically operated selector switches for joining the additional link con-v nectors with the aforesaid link connectors; operator controlled means for governing the operation oit-said selector switches; means ing telephone lines extending from stations' yto an exchange; link connectors at `the exchange for extending calling lines; operattor controlled switching apparatus for joining operator selected link connectors with calling' lines; vadditional link connectors; electro-magnetically operated selector switches for joining the additional link connectors with. the aforesaid link connectors:

automatically operating operator controlled means for governing theoperation of said selector switches and causing them to hecome automaticall Y connected with the lirst aforesaid link connectors when. they are taken for use; means for preventing selector switches from remaining in connection. with operator appropriated link connectors that are in connection with other selector switches; operator controlled electro-mag netica-lljT operated connector switches for connect-ing the selector switches that are connected with operator yappropriat-ed link connectors, with desired lines; operators responsive devices at ditlferent operators7 positions; and selecting mechanism for selecting operators" responsive devices that are free for selectiointhe link connectors performing their vline joining function independently of said selecting -mechanism that selects operators responsive devices.

1S. A telephone exchange system including telephone lines extending from stations to an exchange; link connectors at the eX- change for extending calling lines; operator controlled switching apparatus for joining operator selected link connectors'with calling lines; additionallink connectors; electro-magnetically operated link selector switches for 'joining the additional link con- /Vnectors with the aforesaid Alink connectors;

means governed by said operator controlled I electro magnetically priated link connectors that are in connection with other selector switches; operator controlled electro-magnetically operated connector switches for connecting the selector switches that are connected with operatorappropriated link connectors, with desired lines; operators responsive devices at dif-' ferent operators positions; and selecting mechanism for selecting operators responsive devices that are free for selection, the link connectors performing their line joining function independently of said selecting mechanism that selects operators responsive devices. v

19. A telephone exchange system includ-- ing telephone lines extending from stations to an exchange; link connectors at the exchange for extending calling lines; operator controlled switching apparatus for joining operator selected link connectors with calling lines; additional link connectors; electro-magnetically operated selector switches for joining the additional link connectors with the aforesaid link connectors; automatically operating operator controlled means for governing the extent of operation of said selector switches and causing them to become automatically connected with the i first aforesaid link connectors when they7 are taken for use; and operator controlled operated connector switches for connecting the selector switches that are connected with operator appropriated link connectors7 with desired lines.

20. A telephone exchange system including telephone lines extending froml stations to an exchange; link connectors at the exchange for extending calling lines; operator controlled switching apparatus for joining operator selected link connectors with calling lines; additional link connectors; electro-magnetically operated l link selector switches for oining the additional link connectors with the aforesaid link connectors; means governed by said operator controlled switching apparatus and operating over operator selected link connectors for governing the extent of operation of said selector switchesvto cause them to remain in connection with operator selected link connectors; and operator controlled electro-magnetically operated connector switches for connecting the selector switches that are connected with operator appropriated link connectors, with desired lines.

21. A telephone exchange system including telephone lines extending from stations to an exchange; link connectors at the exchange for extending callinglines; operator controlled switching apparatus for joining operator 'controlled link connectors with calling lines; additional link connectors; electro-magnetically operated selector switches for joining the additional link connectors with the aforesaid link connectors;

operator controlled means for governing 'the v extent of operation of said selector switches;

means for preventing selector switches from remaining 1n connection wlth operator -ap- Apropriated link connectors that are in connection with other selector switches; and operator controlled electro-magnetically operated connector switches forv connecting the selector 'switches that are connected with operator appropriated link connectors, with desired lines.-

22. A telephone exchange system including telephone lines extending from stations to an exchange; link connectors at the exchange for extending calling lines; operator controlled switching apparatus for joining operator selected link connectors with callingv lines; additional link connectors; electrq-magnetically operated selectorv switches for -joining the additional link connectors with the aforesaid link connectors; l' automatically operating operator j controlled means for governing the extent of operation of said selector switches andcausing them to become automatically connected with the first aforesaid link connectors when they are taken for use; means for preventing selector switches from remaining in connec` tion with operator appropriated link connectors that in connection with other selector switches; and operator controlled electroymagnetically operated connector switches switches for joining the additional link connectors with the aforesaid link connectors; means governed by said operator controlled switching apparatus and'operating over operator selected link connectors for governing the extent of operation of said selector Switches to cause them to remain in connection with operator selected link connectors; means for preventingl selector switches from remaining in connection with operator appropriated link connectors that are in connection with other selector switches; and operator controlled electro-magnetically operated connector switchesfor connecting the selector switches that are connected with operator appropriated link connectors,` with desired lines.

24. A telephone exchange system including telephone lines extending from stations to 'an exchange; link connectors atthe exchange for extending calling lines; operator controlled switching apparatus for joining operator controlled link connectors with calling lines; additional link connectors; electro--niagnetically operated selector switches for joining the additional link connectors with the aforesaid link connectors; operator controlled means for governing the extent of automatic operation ot said' se` lectorswitches; operators responsive devices at different operators positions; and selecting mechanism for selecting operators responsive devices that are free'lor selection, the link connectors performing their line joining functions independently of said selecting mechanism that selects operators responsive devices.

A telephone exchange system including telephone lines extending from stations to an exchange; operator controlled switchingr apparatus torl joining operator selected link connectors with calling lines; additional link connectors; electro-magnetically operated selector switches tor joining the additional link connectors with the aforesaid link connectors; automatically operating operator controlled means for governing the extent ot operation of said selector switches and causing them to become automatically connected with the first aforesaid link connectors when they are taken for use; operaators responsive devices at different operators positions; and selecting mechanism tor selecting operators responsive devices that are tree tor selection, the link connectors performing their line joining function independently of said selecting mechanism that selects operators responsive devices.

26. A telephone exchange system including telephone lines extending trom stations toan exchange; link connectors at the exchange tor extending calling lines; operator controlled switching apparatus tor joining operator selected link connectors with calling lines; additional link connectors; electro-niagnetically operated link connector switches `for joining the additional link connectors with the aforesaid link connectors: means governed hy said operator controlled switching apparatus and operating over operator selected link connectors tor governing the extent ot operation oi said selector switches to cause them to remain in 'connection with operator selected link connectors; operators responsive, devices at di ll'crent operators positions; and selecting mechanism for selecting operators responsive devices that are tree for selection7 the link connectors performing their line joining function independently of said selecting mechanism lh at selects operators responsive devices.

ing telephone lines extending .troni stations to an exchange; link connectors at `the exchange Jfor extending calling lines; operator controlled switching apparatus for joining operator controlled link connectors with 27. A telephone exchange system includ- 4 calling lilies; additional link connectors; electro magnetically operated selector switches for joining the additional lilik connectors with the aforesaid link connectors; operator controlled means for governing the extent ot' operation oi' maid selector switches; means for jjireventing selector switches from remaining in connection with operator appropriated link connectors that are in connection with other selector switches; operators responsive devices at diiterent operators positions; and selecting mechanism for selecting operators? responsive'devices `that are tree for selection, the link connectors performing their line joining function indej'iendently ot said selecting n iechanisniy Awith the aforesaid link connectors; automatically operating operator controlled` means 'for governing the extent of operation ol said selector switches and causing them to become automatically connected with the tirst aforesaid .link connectors when the are taken `tor use; means 'tor preventing selector switches froni remaining in connection with operator a ppropriated link connectors that are in connection with other switches; ojjierators responsive devices at ditl'erent operators positions;.and selecting mechanism 'tor selecting operators responsive devices that are tree tor selection. the link connectors performing their line joining function independently ot said selecting niecl'iax'iism that selects operators` responsive devices.

'29. A telephone exchange system including telephone lilies extending trom stations to an exchange; link connectors at the exchange tor extendingcalling lines; ope ator controlled switching apparatus for joining operator selected link connectors with calling lilies; additional link connectors; electro-inagnetically operated link selector switches for joining the additional link connectors with the atpresaid link connectors; means governed by said operator controlled switching apparatus and operating over operator selected link connectors tor governing the extent ot operation ot' said selectorswitches to ca use them to remain in connection with operator selected link connectors; means for preventing selector switches from remaining in connect-ion with operator appropriated link connectors that are in connection with 'other selector switches; operators responsive devices at different opselector l erators ositions and selectin mechanism `for selecting operators responsive devices 'that are free for selection, the link connecoperator controlled link connectors with call# ing lines; additional link connectors; electro-magnetically operated selector switches for joining the additional link connectors .with the aforesaid link connectors; operator controlled means for governing the extent 'of automatic operation of said selector switches; operator controlled electro-magnetically operated connector 4switches for connecting the selector switches that are connected with the operator appropriated link connectors, with desired lines; operators re- 4 sponsive devices at different operators posi- Vmatically operating tions; andselecting mechanism for selecting operators responsive devices that are free for selection, the link connectors performing their line joining function independently of said selecting mechanism that selects operators responsive devices.

3l. A telephone exchange system including telephone lines extending from stations tol an exchange; "link connectors at the exchange for extending calling lines; operator controlled switching apparatus for joining operator selected link connectors with calling lines; additional link connectors; electro-magnetically operated selector switches Afor joining the additional'link connectors with the aforesaid link connectors; autooperator controlled means for governing the extent of operation of said selector switches and causing them to become automatically connected with the iirst aforesaid link connectors when they are taken for use; operator controlled electro-magnetically operated connector switches for connecting the selector switches that are connected with operator appropriated link-connectors, with desired lines; operators responsive devices at diiierent operators positions; and selecting mechanism for selecting operators responsive devices that are free for selection, the link connectors performing their line joining function independently of said selecting mechanism that selects operators responsive devices.

32. A telephone exchange system including telephone lines extending from stations to an exchange; link connectors at the exchange for extending calling lines; operator controlled switching apparatus for joining operator selected linkV connectors with calling lines; additional link connectors; electro-magnetically operated link selector switches for joining the additional.

link connectors with the aforesaid link connectors; means governed by said operator controlled switching apparatus andoperating over operator selected link connectors for governing the extent of operation of said selector switches to cause them to remain in connection with operatorA selected link connectors; operator controlled electron-magnetically operated connector switches for connecting the selector switches that are connected with operator appropriated link connectors, with desired lines; operators responsive devices at diiierent operators positions; and selecting mechanism for selecting operators responsive devices that are free for selection; the link ,connectors performing their line joining function indeoperator appropriated link connectors that are in connection with other selector switches; operator controlled electro-magnetically operated connector switches for connecting the selector yswitches that are connected with operator appropriated link connectors, with desired lines; operators responsive devices at different operators` positions; and selecting mechanism for selecting operators responsive devices that are free :for selection, the link connectors vperforming their line joiningfunction independently of said selecting mechanism thatselects operators responsive devices.

34. A ltelephone exchange system including telephone lines extending from stations to an exchange; link connectors lat the exchange for extending calling lines; operator controlled switching apparatus for joining operator selected link connectors with calling lines; additional linkvconnectors; electro-magnetically operated selected switches for joining the additional link connectors with the vaforesaid link connectors: automatically operating operator controlled means for governing the extent of operation of said selector switches and causing them to become automatically connected with the first aforesz.v d link connectors when they are taken for use; means for preventingselector switches Jfrom remaining in connection with innamora operator appropriated link connectors that are in connection with other selector switches; operator controlled electro-magneticallyoperated selector switches for con nesting the selector switches that are connected with operator appropriated link connectors, with desired lines;l operators responsive devices at different operators po sitions; and selecting mechanism for selecting operators responsive devices that are free for selection, the link connectors per# tors; electro-magnetically operated link se-` lector switches for joining the additional connectors with the aforesaid link con- .fnlectors; means 'governed by said operator controlled switching apparatus and perat# @aptes of this'notent may be obtained for ing overoperator selected. link connectorsor governing the extent of operation of said selector switches to canse them to remain in connection with operator selected '.linkconnectors; means for preventing selector switches from remaining in connection with operator appropriated link connectors that are in connection with other selector switches; operator controlled. electro-magnetically operated connector switches for connecting the selector switches that are connected with operator appropriated link connectors, with desired lines; operators responsive devices at dierent operators positions; and selecting mechanism for selecting operatorsv responsive devices that are free for selection, the link connectors performing their line joining function: independently of said selecting mechanism that selects operators responsive devices.

in Witness whereof? l hereunto subscribe- .my naine this third day of lulJy Ar. D. 1912.

MRTUN L. TSN. Witnesses:

' G. L. CRAGG,

Erm L, VVHrrn.

ve cents each, by addressing the Commtsaoner or Estense, vWe..slrimgtqwn1X3. GL 

